At one point in "Still Alice," the new show at the Lookingglass Theatre based on the novel by Lisa Genova about the emotionally devastating subject of early-onset Alzheimer's disease, a mother does not recognize her own daughter.

It's not that unusual in these cases, of course. Alzheimer's is often referred to as a "long goodbye" or a "slow farewell" or maybe, most accurately, sheer bloody hell for all involved. Those saying farewell include not only family members and colleagues but the sufferer herself, who must wrestle with the forced disappearance of many of the things that make up one's complex but inestimably precious sense of self.

In Genova's book, which has been newly adapted for the stage by Christine Mary Dunford and relocated from Massachusetts to Evanston and Northwestern University, the central character is an accomplished academic, a professor of psychology, an intellectual who, one fine day, discovers that she cannot remember people's names so well, then that she can't find her stuff, then that she does not know her own neighborhood, and on and on. "Still Alice" is not a sequel to the Lookingglass company's famed "Lookingglass Alice," as its title might imply. But there's no question that this Alice also disappears down a rabbit hole. She just has no choice.

Still, needing notes on the refrigerator is one thing. Not recognizing your own family is another. You could feel the waves of anxiety and empathy and dread in the theater as Eva Barr's Alice blinked out at Joanne Dubach's disbelieving Lydia, even as Alice's husband John (Christopher Donahue) and Lydia's brother Thomas (Cliff Chamberlain) looked on with the kind of horror that we all fear entering our lives, especially those of us who already are part way down that road. That act of non-recognition, whether it takes place in a hospital room or a theater, is almost too much to bear, although many people have no choice. There are very few good dramatic explorations of aging (although the 2012 movie "Amour" certainly is on that list). "Still Alice" has themes that touch multitudes of lives. It has the potential to be a very important piece of theater, as that one aching moment surely reveals.

Frankly, there would have been more such moments had Dunford's adaptation, in concert with Dunford's production, not become caught in a couple of traps of its own making.

Barr, a longtime Lookingglass ensemble member who works only occasionally at the theater, has a fascinating, enigmatic, theatrical presence. But "Still Alice" is fundamentally a book about change — a forced change — and the most serious problem with this show is that you never feel like you really see Alice before all these things begin to happen to Alice. To put this another way, Barr rushes out for the play's destination long before we've come to grips with her starting point, her point of reference, her everyday self. We need to witness that beginning if we are to understand and empathize with all that befalls the central character.

Dunford also made the choice to create a kind of alter-ego for Alice. Known as Herself and played by Mariann Mayberry, this character allows Dunford to work in the internal conversations that figure in Genova's novel about highly educated characters in better positions that most to understand the science of Alzheimer's and to navigate the healthcare maze but who, in the end, are no better equipped to deal with the emotional fallout. Mayberry does her considerable best with the role, but the piece would have worked much better if Dunford has challenged herself with truly dramatizing those moments (there already is narrative text on a screen at the rear of the stage). We care about Alice as a person and Alice in concert with her family. Alice talking to Herself (or Herself addressing family members) ends up mostly as a distracting cop-out, especially since it is hard to get a handle on the dramatic rules, since Herself sometimes represents Alice's rational self and, at other moments, seems to be dealing with the same issues as Alice. Tough decisions weren't made.

One can see why Dunford, who took on a lot here by directing her own adaptation, wanted Alice to be in conversation with Alice. In the book, the former Alice offers advice for the changed Alice. But there has to be a more potent dramatic solution.

That said, "Still Alice" explores much that is worthy and features some extraordinarily fine performances, most especially from Donahue, an actor of whom we see far too little, here playing a generally loving husband forced to wrestle with how much he is willing to sacrifice his own career for his wife's new needs. As Donahue so movingly argues (and Chamberlain and Dubach are right there with him), there is no question that the old Alice would not want him to hurt his career. But then, what do you do when the new Alice does not remember that?